Admitted to the Union as the 39th state on August 2, 1874, Cuba was acquired from Spain through the Adams-Onis Treaty of 1819, which also officially transferred East Florida and the remainder of West Florida to American control and defined the western extent of the Louisiana Purchase. Cuba is the 5th largest state in the US, with a population of 20.2 million, behind Luzon, Texas, South California, and North California, and is one of only four states where Spanish is an official second language (the others being Santo Domingo, Panama and Puerto Rico), due to the state's majority Hispanic population of 55.4%.